CN113452428B

CN113452428B - Method for multi-channel CSI scanning, and STA device and AP device for executing same

Info

Publication number: CN113452428B
Application number: CN202110709216.5A
Authority: CN
Inventors: 张园园; 顾胜东; 张军一
Original assignee: Espressif Systems Shanghai Co Ltd
Current assignee: Espressif Systems Shanghai Co Ltd
Priority date: 2021-06-25
Filing date: 2021-06-25
Publication date: 2023-07-14
Anticipated expiration: 2041-06-25
Also published as: CN113452428A

Abstract

A method of performing multi-channel CSI scanning in a wireless local area network WLAN and a STA device and an AP device performing the method. The method mainly comprises the following steps: and acquiring the CSI scanning capability information of the single AP equipment, wherein the CSI scanning capability information at least comprises a scannable channel list of the AP equipment supporting CSI scanning. And based on the CSI scanning capability information, sending a request for joining a CSI scanning group to the single AP equipment, wherein the request for joining the CSI scanning group at least comprises a desired scanning channel list. A request response returned from an AP device to join a CSI scanning group is obtained, wherein the request response to join the CSI scanning group includes at least a response channel list allocated by the single AP device based on the request to join the CSI scanning group by the STA device. Determining whether to join the CSI scanning group based on the request response of joining the CSI scanning group, and if so, returning a CSI receiving frame to the AP equipment; and if not, returning a CSI rejection frame to the AP equipment.

Description

Method for multi-channel CSI scanning, and STA device and AP device for executing same

Technical Field

The present invention relates to the field of wireless communications, and in particular to a method, apparatus and computer device for obtaining channel state information (CSI, channel State Information) of a multi-channel device.

Background

In the current IEEE (Institute of Electrical and Electronics Engineers ) 802.11 standard, CSI (Channel State Information, channel state information) is defined for OFDM (Orthogonal Frequency Division Multiplexing ) modulation. CSI may be represented as channel state information between two wireless devices. More specifically, CSI is a CFR (Channel Frequency Response ) sample in subcarriers within an operating band calculated by a training sequence in an Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) physical layer packet or the like. The channel state information itself is independent of the transmitted signal, depends on the path, reflector, obstacle, etc. experienced during the propagation of electromagnetic waves, and is therefore a depiction of the physical environment between the transmitting end and the receiving end. Based on CSI information between wireless devices, a very wide variety of new applications may be developed, such as indoor positioning, human gesture recognition, motion detection, and the like.

The method for obtaining CSI mainly includes that STA (station, client) equipment is connected with Access Point (AP) equipment to send a sounding packet for obtaining. OFDM or OFDMA partitions the channel into a number of sub-channels, each employing a respective subcarrier signal. Each subcarrier signal may independently carry information. Because the CSI is CFR sampling which is carried out in the working frequency band by taking the subcarriers as a unit, the more the number of the subcarriers acquired by the CSI is, the more comprehensive the CFR information which is characterized by the CFR is, so that the application precision based on the CSI development is higher. Taking 802.11g/n as an example, a certain channel has a bandwidth of 20MHz, namely 64 subcarriers, and if different channels can be further switched to acquire information, richer subcarrier CSI information can be acquired.

In order to obtain CSI information on multiple channels, chinese patent CN111988096 actively scans channels corresponding to each AP device, selects multiple AP devices in a multiple network or a single network, and obtains CSI on corresponding different channels in a channel hopping manner. Chinese patent CN108075847 instructs STA devices to stay passive listening one by one on each channel to be listened recorded in the list according to the listening channel list to receive PPDUs sent from the target AP devices and extract CSI information therefrom, or actively scans beacon frames, probe response frames, etc. of the AP devices on each listening channel on the channel, thereby obtaining CSI on different channels.

According to the method, the CSI information on different channels can be acquired by using a plurality of AP devices on different channels in a non-connection mode. However, the precondition for obtaining CSI information on the corresponding channel in the above implementation is that an AP device is located near the STA device requesting CSI and is operating on the channel. For example, if there is no AP on a certain channel, the collection of multi-channel CSI cannot be achieved. Furthermore, the CSI information on the different channels acquired in these ways characterizes the spatial channel information between the CSI receiving points and the different APs. The spatial information such as distance, azimuth and obstacle between the AP and the STA requesting CSI may have a large difference, so that it is difficult for the CSI to effectively improve the accuracy of identifying channel information between a specific AP device and the STA device requesting CSI.

Accordingly, there is a need in the art for a scheme that can efficiently acquire CSI information on multiple channels, independent of the number and density of AP device deployments.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide a scheme for performing multi-channel CSI scanning.

In an aspect of the present invention, there is provided a method of performing multi-channel CSI scanning, the method being performed by a STA apparatus, the steps comprising:

And acquiring the CSI scanning capability information of the single AP equipment, wherein the CSI scanning capability information at least comprises a scannable channel list of the AP equipment supporting CSI scanning. And based on the CSI scanning capability information, sending a request for joining a CSI scanning group to the single AP equipment, wherein the request for joining the CSI scanning group at least comprises a desired scanning channel list. A request response returned from an AP device to join a CSI scanning group is obtained, wherein the request response to join the CSI scanning group includes at least a response channel list allocated by the single AP device based on the request to join the CSI scanning group by the STA device. Determining whether to join the CSI scanning group based on the request response of joining the CSI scanning group, and if so, returning a CSI receiving frame to the AP equipment; and if not, returning a CSI rejection frame to the AP equipment.

Optionally, the STA device acquires CSI scan capability information of the single AP device according to the received beacon frame or probe response frame sent by the single AP device.

Preferably, the method for determining whether to join the CSI scan group includes: judging whether the response channel list is a superset of a basic scanning channel list of the STA equipment, if so, adding the CSI scanning group; if not, refusing to add the CSI scanning group.

Optionally, after the step of returning the CSI acceptance frame, the method further includes performing a multi-channel CSI scan, including: and acquiring a CSI scanning start frame sent out from the AP equipment, wherein the CSI scanning start frame at least comprises a planned scanning channel list, a scanning start time and a single channel scanning duration of the AP equipment. Extracting all channels expected to be scanned by the STA equipment from a planned scanning channel list in the CSI scanning start frame. And respectively calculating the relative time interval between the time point of transmitting the CSI measurement frame by the AP equipment on each channel of channels expected to be scanned by the STA equipment and the finishing time point of transmitting the CSI scanning start frame by the AP equipment according to the single channel scanning duration time in the CSI scanning start frame. Based on the relative time interval, sequentially switching to corresponding channels in expected scanning channels in the CSI measurement frames sent by the AP equipment at corresponding time points respectively, waiting for receiving the CSI measurement frames sent by the AP equipment, switching to the channel expected to be scanned next by the STA equipment if the waiting time exceeds the single channel scanning duration, and waiting for receiving the CSI measurement frames; and so on, switching to a normal working channel until the current channel scanning execution period is finished.

Preferably, the STA device calculates, according to the received CSI measurement frames, channel state information CSI of channels corresponding to the CSI measurement frames, respectively.

Preferably, the single channel scan duration is a time that the AP device remains on one of the channels in the planned scan channel list.

Preferably, the STA apparatus periodically performs the multi-channel CSI scan, wherein the CSI scan start frame further includes a channel scan execution period. The channel scanning execution period is the time interval between the two times of starting the multi-channel CSI scanning by the AP equipment, namely the time consumed by the AP equipment for traversing all channels in the planned scanning channel list and the time of the AP equipment in a normal working channel are included.

In another aspect of the present invention, there is provided a method of performing multi-channel CSI scanning, the method being performed by an AP device, comprising the steps of:

and transmitting a beacon frame or a probe response frame, wherein the beacon frame or the probe response frame at least comprises the CSI scanning capability information of the AP equipment, and the CSI scanning capability information at least comprises a scannable channel list of which the AP equipment supports CSI scanning. And acquiring requests of joining the CSI scanning groups, which are respectively transmitted by one or more STA devices, wherein the requests of joining the CSI scanning groups at least comprise an expected scanning channel list corresponding to the STA devices. And sending request responses for joining the CSI scanning group to one or more STA devices respectively according to the request for joining the CSI scanning group of the one or more STA devices and the scannable channel list of the AP device supporting the CSI scanning, wherein the request responses for joining the CSI scanning group at least comprise response channel lists respectively distributed to the one or more STA devices by the AP device. Receiving a CSI acceptance frame or a CSI rejection frame from one or more STA devices, and if the CSI acceptance frame is received, adding a response channel list corresponding to the STA device for sending the CSI acceptance frame to a planned scanning channel list of the AP device; and if the CSI refusal frame is received, the planned scanning channel list of the AP equipment is not updated. And judging whether the planned scanning channel list is empty, if so, closing the multi-channel CSI scanning function, and if not, executing multi-channel CSI scanning.

Optionally, the response channel list is a subset of a scannable channel list of the AP device.

Optionally, the method for the AP device to perform multi-channel CSI scanning further includes: the AP device transmits a CSI scan start frame to all STA devices in one or more of the CSI scan groups, wherein the CSI scan start frame includes at least a planned scan channel list, a scan start time, a single channel scan duration. And after the AP equipment finishes transmitting the CSI scanning start frame, extracting a first channel in a planned scanning channel list, and waiting for the scanning start time to be the interval, switching to the first channel by the AP equipment, and transmitting the CSI measuring frame on the first channel. After the scanning start time is spaced, the AP equipment switches to the next channel in the planned scanning channel list after each single channel scanning duration time, and performs the following steps on the current channel after the switching is sent on the channel: the AP equipment sends a CSI measurement frame associated with the current channel; until all channels in the planned scan channel list are traversed. After the AP passes through the single channel scanning duration, and if the current channel is the last channel in the planned scanning channel list, the AP equipment is switched to a normal working channel after the single channel scanning duration; and repeating the steps until the next multi-channel CSI scanning starts.

Optionally, the AP device transmits the CSI measurement frame in at least one of an OFDM scheme, an OFDMA scheme, a BPSK scheme, and a QPSK scheme.

Optionally, the AP device periodically performs the multi-channel CSI scan, wherein the CSI scan start frame further includes a channel scan execution period.

Optionally, the channel scan execution period is a time interval between two starts of multi-channel CSI scanning by the AP device.

In yet another aspect of the present invention, a communication apparatus applied to a STA device is provided.

In yet another aspect of the present invention, a communication apparatus applied to an AP device is provided.

In yet another aspect of the present invention, a computer readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the steps of the multi-channel CSI scanning method described above.

The invention optimizes a multi-channel CSI scanning mode, provides a scheme that STA equipment acquires multi-channel CSI from single AP equipment, wherein one or more STA equipment acquires the multi-channel CSI through the single AP equipment based on channel switching, and particularly provides a simple mode which can realize channel CSI measurement of one or more STA equipment on a plurality of channels only through the single AP equipment. The scheme can improve the stability of multi-channel CSI scanning and the accuracy of CSI information measurement.

The invention at least overcomes the problem brought by the STA equipment obtaining the CSI information on a plurality of channels through different AP equipment in the prior art, namely the invention depends on that the AP equipment works on different channels needing to collect the CSI. In the scheme, the STA equipment can complete the acquisition of the multi-channel CSI only by interacting with one AP equipment. The invention has the other advantage that the CSI of all channels obtained by the technical scheme of the invention represents the channel characteristics of the same space, overcomes the environmental difference possibly brought by measuring the channel CSI by different AP equipment in the prior art, and can effectively improve the identification precision of the channel characteristics in the space.

It is to be understood that the above description of the background and summary is illustrative only and is not intended to be in the nature of a limitation.

Drawings

Fig. 1 is a schematic flow diagram of an AP device transmitting CSI scan capability information supported by the AP device itself to one or more STA devices.

Fig. 2 is a schematic flow chart of a method of a STA device performing multi-channel CSI scanning according to one embodiment of the present invention.

Fig. 3 is a schematic flow chart of a STA joining a CSI scan group of an AP according to one embodiment of the present invention.

Fig. 4 is a schematic diagram of a channel scan execution period of an AP device according to one embodiment of the present invention.

Fig. 5 is a schematic flowchart of an AP device performing CSI scanning in each channel scanning execution period according to one embodiment of the present invention.

Fig. 6 is a schematic flowchart of an STA apparatus performing CSI scanning in each channel scanning execution period according to one embodiment of the present invention.

Fig. 7 is a block diagram of a STA device 700 according to one embodiment of the present invention.

Fig. 8 is a block diagram of an AP device 800 according to one embodiment of the present invention.

Fig. 9 is a flow diagram of an example of multi-channel CSI scanning according to one embodiment of the invention.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, exemplary embodiments. It is to be understood that the embodiments shown in the drawings and described below are merely illustrative and not restrictive of the invention.

Before describing the technical solution of the embodiments of the present application, a description is first given of the communication system of the embodiments of the present application with reference to the accompanying drawings. Referring to fig. 1, a schematic application scenario is provided in an embodiment of the present application. The application scenario includes a plurality of STA devices, for example, STA1, STA2, …, STA n, and AP devices. In the specific implementation process of the embodiment of the application, the STA device is a communication device with a wireless transceiving function, for example, may communicate with other devices based on an 802.11 protocol, for example, may be a device such as a computer, a smart phone, a tablet computer, or an internet of things device working in an STA mode; the AP is a communication device with a wireless transceiver function that can provide services for STAs, for example, can communicate with other devices based on an 802.11 protocol, for example, an access point in an 802.11 wireless lan or an internet of things device operating in an AP mode, etc.

In combination with the application scenario schematic diagram shown in fig. 1, a specific embodiment of the present application is described below. According to the technical solution of the present application, three main scenarios are described below. Wherein, scenario 1 is a CSI scan capability statement for an AP device; scene 2 is that STA equipment joins in the CSI scanning group of AP equipment; scenario 3 performs a multi-channel CSI scan for an AP device and one or more STA devices.

Scene 1: CSI scan capability declaration for AP devices

In connection with fig. 1, the following describes an AP device transmitting CSI scan capability information supported by the AP device itself to one or more STA devices.

The AP device in this embodiment transmits CSI scanning capabilities supported by the AP device itself to one or more STA devices through a broadcast frame.

Optionally, the AP device periodically transmits CSI scanning capabilities supported by the AP device itself to one or more STA devices.

It should be understood that the single AP device CSI scan capability information in this embodiment includes at least a scannable channel list in which the AP device supports CSI scanning.

Optionally, the single AP device CSI scanning capability information in this embodiment may further include at least one of a planned scanning channel list of the AP device, a channel switching time of the AP device, and a channel scanning execution period of the AP device.

Alternatively, the CSI scannability information in this embodiment may be declared by a Information Element (IE, information element) field in the transmitted broadcast frame.

Further, the broadcast frame in this embodiment may be a beacon frame. Still further, the AP device may actively transmit beacon frames.

Further, the broadcast frame in this embodiment may be a probe response frame. Still further, the AP device may transmit a probe response frame in response to the probe request transmission.

By way of example and not limitation, the content of the single AP device CSI scan capability information may be as shown in table 1. Wherein:

the ChannelList is a scannable channel list for supporting CSI scanning by the AP equipment, namely, the channel list indicates that the AP equipment can be switched to any one channel in the scannable channel list, and a CSI measurement frame is sent on the channel. By way of example and not limitation, the CSI measurement frame is a broadcast short frame defined according to the IEEE 802.11G/N/AC/AX protocol, and after any STA device receives the CSI measurement frame, the LTF portion of the CSI measurement frame may be used to calculate channel state information.

ValidChannelList is a planned scan channel list for the AP apparatus, and ValidChannelList is a subset of ChannelList. When no STA device joins the CSI scanning group of the AP device, the ValidChannelList list is empty.

T _{channel_switch} Indicating AP setupThe time it takes to switch channels once is prepared.

T _scan The time interval between two times of starting multi-channel CSI scanning by the AP device is represented, namely the time consumed by the AP device for traversing all channels in the ValidChannelList and the normal communication time of the AP device in a normal working channel are included.

It should be noted that channel switching is the capability that all Wi-Fi protocol enabled devices should support. During the channel switching, the device cannot perform normal communication. Therefore, the shorter the channel switching time should be, the better. The AP device may determine the number of channels to be scanned in a complete multi-channel CSI channel scanning execution period according to its capability of channel switching time, so as to control the scanning time within a certain range, so as to ensure that normal communication is not affected.

Table 1: content of single AP device CSI scanning capability information

Name of the name	Meaning of
		ChannelList	Scannable channel list
ValidChannelList	Planning scan channel list
		T _{channel_switch}	Channel switching time
T _scan	Channel scan execution period

It should be appreciated that after receiving the CSI scanning capability information sent by the AP device, the one or more STA devices send a request to join the CSI scanning group to the AP device if the one or more STA devices wish to join the CSI scanning group of the AP device. The specific method and flow of joining CSI scanning groups by the STA device refers to the description of scenario 2.

Scene 2: CSI scanning group for STA device to join AP device

Fig. 2 is a schematic flow chart of a method of joining a CSI scanning group of an AP device by a STA device according to the present embodiment. As shown in fig. 2, the method comprises the steps of:

s11: the STA equipment acquires CSI scanning capability information of a single AP equipment;

s12: based on the CSI scanning capability information, the STA equipment sends a request for joining a CSI scanning group to the single AP equipment;

s13: the STA equipment acquires a request response returned from the AP equipment to join the CSI scanning group;

s14: the STA equipment determines whether to join the CSI scanning group or not based on the request response of joining the CSI scanning group, and if so, returns a CSI receiving frame to the AP equipment; and if not, returning a CSI rejection frame to the AP equipment.

It should be understood that in step S11, the single AP device CSI scan capability information acquired by the STA device includes at least a scannable channel list in which the AP device supports CSI scanning. In this embodiment, the single AP device CSI scan capability information may further include at least one of a planned scan channel list of the AP device, a channel switching time of the AP device, and a channel scan execution period of the AP device.

Further, the STA device may obtain CSI scan capability information of a single AP device from a broadcast frame sent by the AP device.

It should be understood that in step S12, the STA device transmits a Request (csi_request frame) to join the CSI scan group to the single AP device, including at least a desired scan channel list.

Further, the expected scan channel list in this embodiment may include a channel list in which the STA device collects CSI information according to actual application needs.

Further, the desired scan channel list in this embodiment is a subset of the scannable channel list of the AP device.

For example, the content of the request sent by the STA device to join the CSI scan group may be as shown in table 2.

TABLE 2

Name of the name	Meaning of
		ReqChannelList	Expected scan channel list

It should be understood that, in step S13, the request response returned from the AP device to join the CSI scan group includes at least a response channel list allocated by the single AP device based on the request to join the CSI scan group sent by the STA device.

Further, the AP device may send a CSI request response frame to the STA device, including the response channel list.

Further, the AP device determines a response channel list according to the scannable channel list supported by itself, the planned scan channel list, and the expected scan channel list transmitted by the STA device.

Further, the response channel list may be a subset of a scannable channel list supported by the AP device itself to ensure that the multi-channel CSI scan does not affect the normal communications of the AP device itself.

For example, the content of the response channel list transmitted by the AP device may be as shown in table 3. Wherein, the respschanelist may be a subset of the ChannelList determined by the AP device according to its own CSI scanning capability.

Name of the name	Meaning of
		RespsChanelList	Responsive channel list

It should be appreciated that in step S14, the method of determining whether to join the CSI scan group includes: judging whether the response channel list is a superset of a basic scanning channel list of the STA equipment, if so, adding the CSI scanning group; if not, refusing to add the CSI scanning group.

By way of example and not limitation, any CSI application of a STA device typically includes one best scan channel list and one basic scan channel list. The basic scanning channel list of the CSI application indicates that the STA device at least needs to acquire CSI information of all channels in the list, and then can ensure the operation of the corresponding CSI application on the STA device.

Further, the STA device may transmit a CSI Accept frame (csi_accept frame) to the AP device to indicate that the CSI scan group of the AP device is received and joined.

Further, the STA device may transmit a CSI rejection frame (csi_deny frame) to the AP device to indicate rejection of joining the CSI scanning group of the AP device.

With reference to fig. 3, it should be understood that after the end of step S14, the AP device updates the scheduled scan list channel, including: if the AP equipment receives the CSI_Accept frame from one or more STA equipment, the AP equipment takes a response channel list sent to the one or more STA equipment as a planned scanning channel list for the multi-channel CSI scanning; if the AP device receives only the csi_deny frame from one or more STA devices and does not receive the csi_accept frame, the AP device continues to use the original scheduled scan channel list as the scheduled scan channel list for the present multi-channel CSI scan.

With reference to fig. 3, further, the AP device determines whether the planned scanning channel list is empty, if so, which indicates that there is no STA device currently that needs to perform multi-channel CSI collection, the AP device turns off the multi-channel CSI scanning function; if not, the CSI scanning group is established, and multi-channel CSI scanning is executed.

Scene 3: AP device and one or more STA devices perform multi-channel CSI scanning

As described in scenario 2, after the AP device establishes the CSI scan group, the AP initiates a periodic multi-channel CSI scan collection task to all STA devices in the scan group.

Referring to fig. 4, 5 and 6, the specific implementation steps of the multi-channel CSI scan are as follows:

Fig. 4 shows a schematic diagram of a channel scan execution period of an AP device. Wherein the channel scan execution period (T _scan ) The time interval between the two times of starting the multi-channel CSI scanning by the AP equipment is the time interval, namely the time consumed by the AP equipment for traversing all channels in the planned scanning channel list and the normal communication time of the AP equipment in a normal working channel. The normal operating channel is the primary channel of the AP device.

It should be understood that the AP device initiates a multi-channel CSI scan every other channel scan execution period, and otherwise communicates normally. The single channel scanning execution period time is longer than the CSI scanning time of the AP equipment in one channel scanning execution period. By way of example and not limitation, during a channel scan execution period, the time spent by an actual AP device scanning channels is only a small fraction, and most of the time is for the AP device to communicate normally on a normal operating channel. By way of example and not limitation, a channel scan execution period (T _scan ) The channel scan execution period is 100ms and the time for the ap device to scan all channels is 1ms, i.e. every timeA multi-channel CSI scan is initiated for 100ms and the AP device spends 1ms performing channel scan, the remaining 99ms communicating normally.

Further, the CSI scan capability information of the AP device includes the channel scan execution period, and the AP device informs all STA devices of the channel scan execution period by sending the CSI scan capability information.

By way of example and not limitation, the CSI scan duration is equal to a single channel scan duration (T _{channel_switch} ) And the number of planned scan channels within a channel scan execution period is related, and the CSI scan duration is equal to the product of the two.

A schematic flowchart of the AP device side and the STA device side performing CSI scanning in each channel scanning execution period is described with reference to fig. 5 and 6, respectively. It should be appreciated that in the solutions described in this disclosure, a single AP device may perform CSI scans on multiple channels with one or more STA devices during each channel scan execution period.

Fig. 5 shows a schematic flowchart of the AP device performing CSI scanning in each channel scanning execution period, and the specific steps are as follows:

step S111: the AP equipment sends a CSI scanning Start frame (CSI_Start frame) to all STA equipment in the CSI scanning group;

step S112: after the completion of the transmission of the CSI_Start frame, the AP equipment extracts a first channel in a planned scanning channel list, and after waiting for a scanning Start time (Tstart), the AP equipment switches to the first channel and transmits a CSI measurement frame on the first channel;

Step S113: each time the AP device passes a single channel scan duration (T _{channel_switch} ) Switching to a next channel in the planned scanning channel list, and transmitting a CSI measurement frame on the channel; until all channels in the planned scanning channel list are traversed, and step S114 is entered;

step S114: after the single channel scanning duration, the AP device switches to a normal operating channel until the next multi-channel CSI scanning starts, and repeats steps S111 to S114.

It should be understood that the CSI scan start frame described in step S111 includes at least: a plan scan channel list, a scan start time, a single channel scan duration.

Further, the CSI scan start frame in step S111 includes at least a channel scan execution period (T _scan ) The time interval between two times of starting multi-channel CSI scanning by the AP device is represented, namely the time consumed by the AP device for traversing all channels in the planned scanning channel list and the normal communication time of the AP device in a normal working channel are included.

By way of example and not limitation, the AP device described in step S112 or step S113 transmits the CSI measurement frame on the channel by at least one of OFDM scheme, OFDMA scheme, BPSK scheme, QPSK scheme.

Further, the CSI measurement frame is associated with a transmission channel through which it passes. Through the received CSI measurement frame, the STA device can calculate CSI information on the corresponding transmission channel based on the received CSI measurement frame.

Fig. 6 shows a schematic flowchart of the STA apparatus performing CSI scanning in each channel scanning execution period, and the specific steps are as follows:

step S41: the STA device acquires a CSI scanning Start frame (CSI_Start frame) sent from the AP device;

step S42: the STA equipment extracts all expected scanning channels of the STA equipment from a planned scanning list in a CSI_Start frame;

step S43: the STA device scans duration (T) according to a single channel in the csi_start frame _{channel_switch} ) Respectively calculating a relative time interval between a time point when the AP equipment transmits the CSI measurement frame on each channel in the expected scanning channels of the STA equipment and a completion time point when the AP equipment transmits the CSI_Start frame;

step S44: based on the relative time interval, the STA device sequentially switches to a corresponding channel in the expected scanning channels at a corresponding time point and waits for receiving the CSI measurement frame sent by the AP device, and if the waiting time exceeds the single channel scanning duration, switches to a channel which is expected to be scanned next by the STA device and waits for receiving the CSI measurement frame; and switching to a normal working channel until the current channel scanning execution period is ended.

Scene 4: de-association of CSI scan groups for AP devices

For an established scan group, the AP device may break up the CSI-scan group by broadcasting a transmit CSI-scan group break up frame during normal communication time. After receiving the CSI-scanning group resolution frame, the STA device may re-execute the request for joining the CSI-scanning group as needed. By way of example and not limitation, one typical example scenario is where an AP device discovers that multiple STA devices in a current CSI-scanning group have been disconnected, then the current CSI-scanning group is broken by broadcasting a transmit CSI-scanning group break-away frame.

For the STA equipment which has joined in the CSI scanning group, if the CSI information collection is not needed in a specific time, the CSI scanning action of the STA equipment is only needed to be closed, and the AP equipment is not needed to be informed.

Fig. 7 illustrates STA device 700 in one embodiment. As shown in fig. 7, the STA apparatus 700 is configured to include: the receiving module 702, the sending module 704 and the processing module 706 are coupled with each other. The receiving module 702 is configured to receive CSI scan capability information sent by a single AP device, where the CSI scan capability information includes at least a scannable channel list that the AP device supports CSI scanning. The sending module 704 is configured to send a request to join a CSI scanning group to the single AP device based on the CSI scanning capability information, where the request to join the CSI scanning group includes at least a desired scanning channel list. Further, the receiving module is further configured to obtain a request response for joining the CSI scanning group returned from the AP device, where the request response for joining the CSI scanning group includes at least a response channel list allocated by the single AP device based on the request for joining the CSI scanning group of the STA device. The processing module 706 is configured to determine whether to join the CSI scanning group based on the request response of joining the CSI scanning group, and if so, return, by the sending module, a CSI acceptance frame to the AP device; and if not, returning a CSI rejection frame to the AP equipment through a sending module. Further, the receiving module 702 may further include obtaining CSI measurement frames sent from the single AP device. Further, the processing module 706 obtains channel state information CSI of the corresponding channel based on the CSI measurement frame. By way of example and not limitation, the CSI measurement frame is a broadcast short frame defined according to the IEEE 802.11G/N/AC/AX protocol, and the processing module 706 may calculate channel state information based on the LTF portion of the CSI measurement frame.

It should be understood that the practice of the invention is not so limited. The components of the STA device of the present invention may be connected in a manner different from that shown.

By way of example, and not limitation, the processing circuit 706 may be implemented as a sequencing circuit implemented on hardware, or as one or more Application Specific Integrated Circuits (ASICs), or Field Programmable Gate Arrays (FPGAs).

Fig. 8 illustrates an AP device 800 in one embodiment. As shown in fig. 8, the AP device 800 is configured to include: the system comprises a sending module 802, a receiving module 804 and a processing module 806, and the three are mutually coupled. The sending module 802 is configured to send CSI scan capability information of the AP device, where the CSI scan capability information includes at least a scannable channel list that the AP device supports CSI scanning. The receiving module 804 is configured to obtain a request for joining a CSI scan group sent by one or more STA devices, where the request for joining the CSI scan group includes at least a list of expected scan channels corresponding to the STA devices. Further, the sending module 802 is further configured to send a request response for joining the CSI scanning group to the respective one or more STA devices according to the request for joining the CSI scanning group of the one or more STA devices and the scannable channel list that the AP device supports CSI scanning, where the request response for joining the CSI scanning group includes at least a response channel list that the AP device allocates to the respective one or more STA devices. Further, the receiving module 804 is further configured to receive a CSI accept frame or a CSI reject frame from one or more STA devices, and if the CSI accept frame is received, add a response channel list corresponding to the STA device that sends the CSI accept frame to a planned scanning channel list of the AP device; if the CSI refusal frame is received, the planned scanning channel list of the AP equipment is not updated; the processing module 806 is configured to determine whether the planned scan channel list is empty, if so, turn off the multi-channel CSI scanning function, and if not, perform periodic multi-channel CSI scanning. Further, the sending module 802 is further configured to send a CSI scan start frame and a CSI measurement frame to one or more STA devices.

As an example of a specific embodiment, a specific application scenario is described below:

as shown in fig. 9, the AP device establishes a CSI scan group with the STA1 device and the STA2 device and prepares to perform multi-channel CSI scanning. In the present multi-channel CSI scan, the planned scan channels of the AP device include channel 1, channel 3, channel 5, and channel 7, i.e., the AP device will traverse these four channels in the present scan execution period. Furthermore, the expected scan channels for STA1 devices are channel 1 and channel 5, and the expected scans for STA2 devices are channel 3 and channel 7.

The AP device first sends csi_start frames to the STA1 device and the STA2 device to indicate that the multi-channel CSI scan starts. The csi_start frame includes a planned scan channel list, a scan Start time, and a single channel scan duration.

After receiving the csi_start frame sent by the AP device, the STA1 device and the STA2 device calculate, according to the expected channel list of the AP device, the scan channel list in the csi_start frame of the AP device, the scan Start time, and the single channel scan duration, the time when the AP device sends the CSI measurement frame in each expected channel list. For example, if the expected scan channels of the STA1 device include channel 1 and channel 5, the STA1 device obtains the time when the AP device transmits the measurement frames on channel 1 and channel 5 according to the parameters in the csi_start frame, and switches to the corresponding channel 1 or channel 5 at the corresponding time point, and waits for and receives the CSI measurement frames transmitted by the AP device. If, at the point in time when the AP device transmits the measurement frame on the channel 5, the STA1 device still does not receive the CSI measurement frame of the channel 3, it switches to the channel 5, and waits to receive the CSI measurement frame on the channel 5. Similarly, if the expected scan channels of the STA2 device include channel 3 and channel 7, the STA2 device obtains the time when the AP device transmits the measurement frames on channel 3 and channel 7 according to the parameters in the csi_start frame, and switches to the corresponding channel 1 or channel 5 at the corresponding time point, and waits for and receives the CSI measurement frames transmitted by the AP device.

After the AP device traverses all channels on the planned scan channel list (channels 1, 3, 5, 7 in this example), the AP device and STA1 device and STA2 device switch to normal operating channels until the AP device initiates the next multi-channel CSI scan.

It should be appreciated that the multi-channel CSI scanning process described above is dominated by the AP device and that one or more STA devices interact with the AP device simultaneously. The process starts with the AP device transmitting the csi_start frame, only the AP device transmits packets during the whole period, and all STA devices selectively receive the measurement frames on the corresponding channels, so there is no situation that multiple STA devices compete for interference.

The above embodiments give specific operation procedures and steps by way of example, but it should be understood that the scope of the present invention is not limited thereto.

According to the method and apparatus disclosed in the present invention, as an alternative implementation method, the steps of any of the methods in the above specific embodiments may be performed using a computer program and stored on a computer readable storage medium.

While various embodiments of the various aspects of the present invention have been described for the purposes of this disclosure, it should not be construed that the teachings of this disclosure are limited to these embodiments. Features disclosed in one particular embodiment are not limited to that embodiment, but may be combined with features disclosed in a different embodiment. Furthermore, it should be understood that the method steps described above may be performed sequentially, in parallel, combined into fewer steps, split into more steps, combined and/or omitted in a different manner than described. It will be understood by those skilled in the art that there are many more alternative embodiments and variations that the above-described components and constructions may be varied or modified without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method of performing multi-channel CSI scanning, the method performed by a STA device, comprising:

acquiring CSI scanning capability information of a single AP device, wherein the CSI scanning capability information at least comprises a scannable channel list of the AP device supporting CSI scanning;

transmitting a request for joining a CSI scanning group to the single AP device based on the CSI scanning capability information, wherein the request for joining the CSI scanning group at least includes a desired scanning channel list;

acquiring a request response of joining the CSI scanning group returned from the AP device, wherein the request response of joining the CSI scanning group at least comprises a response channel list allocated by the single AP device based on the request of joining the CSI scanning group of the STA device;

determining whether to join the CSI scanning group based on the request response of joining the CSI scanning group, and if so, returning a CSI receiving frame to the AP equipment; if not, returning a CSI rejection frame to the AP equipment;

after the step of returning the CSI acceptance frame, the method further includes performing a multi-channel CSI scan, including:

acquiring a CSI scanning start frame sent from an AP device, wherein the CSI scanning start frame at least comprises a planned scanning channel list, scanning start time and single channel scanning duration of the AP device;

And calculating the time of the AP equipment for transmitting the CSI measurement frames on each expected scanning channel of the STA equipment according to the expected scanning channel list, the planned scanning channel list in the CSI scanning start frame, the scanning start time and the single channel scanning duration, switching to the corresponding expected scanning channel at the corresponding time point, and waiting for receiving the CSI measurement frames transmitted from the AP equipment.

2. The method of claim 1, wherein the STA device obtains CSI scan capability information of the single AP device based on the received beacon frame or probe response frame transmitted by the single AP device.

3. The method of claim 1, wherein the method of determining whether to join the CSI scan group comprises:

judging whether the response channel list is a superset of a basic scanning channel list of the STA equipment, if so, adding the CSI scanning group; if not, refusing to add the CSI scanning group.

4. A method according to any of claims 1-3, characterized in that calculating the time at which the AP device transmits CSI measurement frames on the respective desired scanning channels of the STA device and switching to the respective desired scanning channels at the respective points in time comprises:

Extracting all expected scanning channels of the STA equipment from a planned scanning channel list in the CSI scanning start frame;

according to the single channel scanning duration time and the scanning starting time in the CSI scanning starting frame, respectively calculating the relative time interval between the time point of transmitting the CSI measurement frame by the AP equipment on each channel in the expected scanning channels of the STA equipment and the completion time point of transmitting the CSI scanning starting frame by the AP equipment;

based on the relative time interval, sequentially switching to corresponding channels in the expected scanning channels at corresponding time points, waiting for receiving the CSI measurement frames sent by the AP equipment, switching to the next expected scanning channel of the STA equipment, and waiting for receiving the CSI measurement frames if the waiting time exceeds the single channel scanning duration; and the like, switching to a normal working channel until the multi-channel CSI scanning is finished.

5. The method of claim 4 wherein the STA device calculates channel state information CSI for the channels corresponding to each CSI measurement frame based on the received CSI measurement frames.

6. The method of claim 4, wherein the single channel scan duration is a time that the AP device remains on one of the channels in the list of planned scan channels.

7. The method of claim 4, wherein the STA device periodically performs the multi-channel CSI scan, wherein the CSI scan start frame further comprises a channel scan execution period.

8. The method of claim 7, wherein the channel scan execution period is a time interval between two starts of multi-channel CSI scanning by the AP device.

9. A method of performing multi-channel CSI scanning, the method performed by an AP device, comprising:

transmitting a beacon frame or a probe response frame, wherein the beacon frame or the probe response frame at least comprises CSI scanning capability information of the AP equipment, and the CSI scanning capability information at least comprises a scannable channel list of which the AP equipment supports CSI scanning;

acquiring requests of joining a CSI scanning group, which are respectively transmitted by one or more STA devices, wherein the requests of joining the CSI scanning group at least comprise an expected scanning channel list corresponding to the STA devices;

according to the request of joining the CSI scanning group of one or more STA devices and the scannable channel list of the AP device supporting the CSI scanning, sending request response of joining the CSI scanning group to one or more STA devices respectively, wherein the request response of joining the CSI scanning group at least comprises a response channel list which is respectively distributed to the one or more STA devices by the AP device;

Receiving a CSI acceptance frame or a CSI rejection frame from one or more STA devices, and if the CSI acceptance frame is received, adding a response channel list corresponding to the STA device for sending the CSI acceptance frame to a planned scanning channel list of the AP device; if the CSI refusal frame is received, the planned scanning channel list of the AP equipment is not updated;

judging whether the planned scanning channel list is empty or not, if so, closing the multi-channel CSI scanning function, and if not, executing multi-channel CSI scanning;

the performing multi-channel CSI scanning includes:

the AP equipment sends a CSI scanning start frame to all STA equipment in the CSI scanning group, wherein the CSI scanning start frame at least comprises a planned scanning channel list, scanning start time and single channel scanning duration;

the AP equipment extracts a first channel in a planned scanning channel list after the transmission of the CSI scanning starting frame is completed, switches to the first channel after waiting intervals are the scanning starting time, and transmits a CSI measuring frame on the first channel;

switching to the next channel in the planned scanning channel list after the single channel scanning duration time passes by the AP equipment, and sending a CSI measurement frame on the channel; and the AP equipment is switched to a normal working channel until all channels in the planned scanning channel list are traversed.

10. The method of claim 9, wherein the response channel list is a subset of a scannable channel list of the AP device.

11. The method according to claim 9 or claim 10, wherein the performing a multi-channel CSI scan comprises:

the AP equipment initiates a multi-channel CSI scanning every other channel scanning execution period.

12. The method of claim 11, wherein the AP device transmits the CSI measurement frame in at least one of an OFDM scheme, an OFDMA scheme, a BPSK scheme, and a QPSK scheme.

13. The method of claim 11, wherein the AP device periodically performs the multi-channel CSI scan, wherein the CSI scan start frame further comprises a channel scan execution period.

14. The method of claim 13, wherein the channel scan execution period is a time interval between two starts of multi-channel CSI scanning by the AP device.

15. A communications apparatus for use with a STA device, comprising:

a receiving module, configured to receive CSI scan capability information sent by a single AP device, where the CSI scan capability information at least includes a scannable channel list that the AP device supports CSI scanning;

A sending module, configured to send a request for joining a CSI scanning group to the single AP device based on the CSI scanning capability information, where the request for joining the CSI scanning group includes at least a desired scanning channel list;

the receiving module is further configured to obtain a request response for joining the CSI scanning group returned from the AP device, where the request response for joining the CSI scanning group includes at least a response channel list allocated by the single AP device based on the request for joining the CSI scanning group of the STA device;

the communication device further comprises a processing module, a transmitting module and a receiving module, wherein the processing module is used for determining whether to join the CSI scanning group or not based on the request response of joining the CSI scanning group, and if so, the transmitting module returns a CSI receiving frame to the AP equipment; if not, returning a CSI rejection frame to the AP equipment through a sending module;

the receiving module is further configured to obtain a CSI scan start frame sent from an AP device, where the CSI scan start frame includes at least a planned scan channel list of the AP device, a scan start time, and a single channel scan duration;

the processing module is further configured to extract all expected scan channels of the STA device from a planned scan channel list in the CSI scan start frame; and

The processing module is further configured to calculate, according to the expected scan channel list and the planned scan channel list, the scan start time, and the single channel scan duration in the CSI scan start frame, a time when the AP device transmits the CSI measurement frame on each expected scan channel of the STA device, and switch to a corresponding expected scan channel at a corresponding time point, and wait for receiving the CSI measurement frame transmitted from the AP device;

wherein the receiving module further comprises obtaining CSI measurement frames sent from the single AP device;

and the processing module acquires Channel State Information (CSI) of a corresponding channel based on the CSI measurement frame.

16. A communication apparatus applied to an AP device, comprising:

a sending module, configured to send CSI scan capability information of the AP device, where the CSI scan capability information at least includes a scannable channel list that the AP device supports CSI scanning;

a receiving module, configured to obtain requests for joining CSI scan groups sent by one or more STA devices, where the requests for joining CSI scan groups at least include a list of expected scan channels corresponding to the STA devices;

the sending module is further configured to send a request response for joining the CSI scanning group to one or more STA devices according to the request for joining the CSI scanning group of the one or more STA devices and the scannable channel list that the AP device supports CSI scanning, where the request response for joining the CSI scanning group includes at least a response channel list allocated by the AP device to the one or more STA devices;

The receiving module is further configured to receive a CSI accept frame or a CSI reject frame from one or more STA devices, and if the CSI accept frame is received, add a response channel list corresponding to the STA device that sends the CSI accept frame to a planned scanning channel list of the AP device; if the CSI refusal frame is received, the planned scanning channel list of the AP equipment is not updated;

the communication device also comprises a processing module, a channel scanning module and a channel scanning module, wherein the processing module is used for judging whether a planned scanning channel list is empty, if so, the multi-channel CSI scanning function is closed, and if not, the periodic multi-channel CSI scanning is executed;

the sending module is further used for sending a CSI scanning start frame and a CSI measurement frame to one or more STA devices;

the sending module is further configured to:

transmitting a CSI scan start frame to all STA devices in the CSI scan group, wherein the CSI scan start frame includes at least a planned scan channel list, a scan start time, a single channel scan duration;

after the transmission of the CSI scanning start frame is completed, extracting a first channel in a planned scanning channel list, and after waiting for the scanning start time, switching to the first channel by the AP equipment, and transmitting a CSI measurement frame on the first channel;

Switching to a next channel in the planned scanning channel list after each single channel scanning duration, and transmitting a CSI measurement frame on the channel; and switching to a normal working channel until all channels in the planned scanning channel list are traversed.

17. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 8.

18. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 9 to 14.